Which of the following is an organic compound?

The correct option is C

$\to$ Organic compounds are any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen or nitrogen.

Now, if you look at the options, only $C{H}_4$ has a carbon atom.

The most important thing in an organic compound is the presence of the carbon atom.